Cookiemonster - What size Happy Heinys are you using? I just had a look at the website & saw that they make XL & XXL!!!
I have one size nappies!!

Howmuch does DS weigh? My DS weighs about 11kg, but a shortie.
HH has four size snaps, we're on the third for daytimes and the fourth for superboosted night nappies. With the velcro, top tab still crosses over the bottom tab around his waist, so i find them to have been a fantastic fit.